Strategies to prevent underage drinking.

Alcohol use by underage drinkers is a persistent public health problem in the United States, and alcohol is the most commonly used drug among adolescents. Accordingly, numerous approaches have been developed and studied that aim to prevent underage drinking. Some approaches are school based, involving curricula targeted at preventing alcohol, tobacco, or marijuana use. Other approaches are extracurricular, offering activities outside of school in the form of social or life skills training or alternative activities. Other strategies strive to involve the adolescents' families in the prevention programs. Policy strategies also have been implemented that have increased the minimum legal drinking age, reduced the commercial and social access of adolescents to alcohol, and reduced the economic availability of alcohol. Approaches involving the entire community also have been employed. Several programs (e.g., the Midwestern Prevention Project and Project Northland) have combined many of these strategies.

U nderage drinking is a persistent public health problem in the United States. Alcohol use ini tiation rates for children rise quickly from age 10 up to about age 13, when they reach more than 50 percent. Subsequently, initiation rates begin to slow again (Kosterman et al. 2000). Moreover, alco hol is the most commonly used drug among adolescents. For example, among eighth-grade students (who are ages 13 to 14) surveyed in the 1999 national representative sample of the Monitoring the Future study, 52 percent reported having consumed alcohol in their lifetime, and 25 percent reported having been drunk in their lifetime. In addi tion, 24 percent of the eighth graders reported having used alcohol in the past month and 9 percent reported having been drunk in the past month (Johnston et al. 2000). These rates are higher than those for use of tobacco or any illegal drug (Johnston et al. 2000).
A strong relationship appears to exist between alcohol use among youth and many social, emotional, and behavioral problems, such as using illegal drugs, fighting, stealing, driving under the influence of alcohol and/or other drugs, skipping school, feeling depressed, and deliberately trying to hurt or kill themselves. In addition to the problems that occur during adolescence, early initia tion of alcohol consumption is related to alcohol-related problems later in life. One study found that early onset of alcohol use (i.e., by age 12) was associ ated with subsequent alcohol abuse and related problem behaviors in later ado lescence, including alcohol-related vio lence, injuries, drinking and driving, absenteeism from school or work, and increased risk for using other drugs (Gruber et al. 1996). Another study found that people who begin drinking before age 15 are 4 times more likely to develop alcohol dependence during their lifetime than are people who begin drinking at age 21 (Grant and Dawson 1997). Therefore, it is clearly an impor tant public health goal to delay the ini tiation of alcohol use among young adolescents for the benefit of their current and long-term health.
To develop effective programs to prevent alcohol use among young ado lescents, it is necessary to first identify the causes of use. The identification of those causes involves a combination of theory and research. According to the theory of triadic influence (TTI), which integrates many behavioral theories into a comprehensive "mega-theory" of health behavior, all behaviors have roots in three domains: the person's personal characteristics, current social situation, and cultural environment (Flay and Petraitis 1994). The TTI also specifies different levels of influence on behavior for various factors. For example, proxi mal factors directly pertain to the drinker (e.g., attitudes and perceived norms around alcohol) and more distal factors pertain to the drinker's environment (e.g., parental practices or laws and poli cies influencing access to alcohol).
Consistent with the TTI, personal, social, and environmental factors repeatedly have been found to be asso ciated with alcohol use among adoles cents (Hawkins et al. 1992;Komro et al. 1997). Personal influences promot ing alcohol use include rebelliousness, tolerance of deviance, a high value on independence and nonconformance, low school commitment and achieve ment, positive beliefs and attitudes toward alcohol use, and lack of selfefficacy to refuse offers of alcohol. Social influences favoring adolescent alcohol use include low socioeconomic status and minimal parental education, family disruption and conflict, weak family bonds, low parental supervision, parental permissiveness and lack of rules about alcohol use, family history of alcoholism, peer alcohol use, perceived adult approval of use, and perceived peer approval of use. Important environmental influ ences on youth alcohol use include the legal, economic, and physical availabil ity of alcohol as well as cultural norms around use.
This theoretical framework, which is supported by research on risk and protective factors (i.e., etiological research), provides a comprehensive understanding of the factors that influ ence the onset of alcohol use among adolescents. Furthermore, the framework offers practical guidance on developing strategies to prevent adolescent alcohol use. Indeed, the enhanced understand ing of the interrelatedness of personal, social, and environmental factors in determining behavior has influenced prevention efforts considerably. Thus, the focus of prevention approaches has broadened from individual personality characteristics to the social world of the adolescent (e.g., family and peers) and to macrolevel environmental factors (e.g., community and societal messages, norms, and availability) (Perry et al. 1993a;Wagenaar and Perry 1994).
As researchers and clinicians develop comprehensive approaches to the pre vention of adolescent alcohol use, they must continue to identify the most important characteristics of different intervention strategies that contribute to the strategies' effectiveness. The fol lowing sections and the table summarize current knowledge regarding the most promising components of the whole spectrum of prevention approaches, including school, extracurricular, fam ily, policy, and community strategies.

School Strategies
The goal of many school-based programs is to reduce the onset and preva lence of adolescent alcohol use by decreasing personal and social risk fac tors and strengthening personal and social protective factors. Several success ful tobacco, alcohol, and marijuana pre vention curricula exist, including Life Skills Training (Botvin et al. 1995), Project Northland , the Midwestern Prevention Project (Pentz et al. 1989), Project SMART (Hansen and Graham 1991), and Project ALERT (Ellickson et al. 1993). These programs have given researchers a better understanding of important components for classroom-based programs. Both meta-analyses (e.g., Tobler 1992;Tobler et al. 2000) and reviews of effective programs (Drug Strategies 1996;Dusenbury and Falco 1995)  Several studies have compared the effectiveness of different types of school-based programs. For example, two recent meta-analyses compared interactive with noninteractive curric ula. Interactive curricula include the components described above, with a substantial amount of time spent in activities that foster the development of interpersonal skills. Noninteractive curricula are more lecture oriented and stress drug knowledge or affective development (i.e., personal insight, self-awareness, and values). The analy ses found that interactive curricula were more effective than noninteractive curricula in preventing alcohol, tobacco, and other drug use among youth (Tobler and Stratton 1997;Tobler et al. 2000).
Interactive programs can be further divided into three categories based on their focus on social influences, com prehensive life skills, and system-wide change, respectively. Of these three cate gories, the system-wide change programs were most effective in preventing overall drug use (including alcohol use), fol lowed by comprehensive life skills and social influences programs (Tobler et al. 2000). System-wide change programs, in turn, are of two types: (1) school-based programs that are actively supported by family and/or community (e.g., Project Northland, which is described below in the section "Multicomponent Strategies") and (2) programs that provide a support ive school environment but do not involve the family and/or community.
A more recent meta-analysis exam ined the relative effectiveness of two types of interactive programs-compre hensive life skills programs and social influences programs-and determined specific drug use outcomes for both strategies (Roona et al. in press). In con trast to the findings by Tobler and col leagues (2000), the results indicated that the social influences programs were sig nificantly more effective than the com prehensive life skills programs in reduc ing alcohol abuse, especially for youth in middle school, where most prevention curricula are implemented. The differ-  Ashery et al. 1998;Etz et al. 1998; National Institute on Drug Abuse (NIDA) 1997 d Grossman et al. 1994;Holder et al. 1997;Lockhart et al. 1993;Perry et al. in press;Wagenaar et al. 2000a,b;Wagenaar and Toomey 2000 ences in findings probably stem from the fact that Tobler and colleagues (2000) studied the effects of the programs on overall drug use, whereas the study by Roona and colleagues (in press) was specific to alcohol abuse. Overall, however, the investigators con cluded that neither program type sig nificantly reduced alcohol use preva lence and that comprehensive life skills programs actually increased alcohol use. These findings may be explained by the fact that alcohol use is highly ingrained in U.S. culture and is the most difficult type of drug to prevent among adolescents using classroombased programs.
The study by Roona and colleagues (in press) included only results on program effectiveness over the first year after the intervention. It is also important, however, to consider more long-term results when analyzing the effectiveness of prevention programs. Such longterm analyses have been conducted for several programs, demonstrating that some result in long-term reductions of tobacco and marijuana use, but not alcohol use, among adolescents (Ellickson et al. 1993;Pentz et al. 1989;Johnson et al. 1990). This finding again supports the greater resistance of alcohol use behavior to change.
The sole curricula-only prevention program that has reported long-term effects on alcohol use is Life Skills Training (Botvin et al. 1990(Botvin et al. , 1995. This program consists of 3 years of prevention curricula for middle or junior-high school students and includes 15 sessions during the first year, 10 sessions during the second year, and 5 sessions during the third year. The curricula cover drug information, drug-resistance skills, self-management skills, and general social skills. A longterm followup study indicated that this program had long-term effects on tobacco, alcohol, and marijuana use through grade 12 (Botvin et al. 1995); however, no alcohol results were reported in the article presenting results from 1 year past high school .
The Life Skills Training curricula focus on changes only at the individual level. A recent etiological analysis, however, indicates that individual-level variables only account for a small percentage of the variance in alcohol use among ado lescents . Accordingly, Griffin and colleagues (2000) concluded that classroom-based prevention efforts should be comple mented with family, community, and policy initiatives that facilitate change in the larger social environment. Such approaches are reviewed in the follow ing sections.

Extracurricular Strategies
About 40 percent of adolescents' waking hours are discretionary-not committed to such activities as eating, school, homework, chores, or working for pay-and many young adolescents spend virtually all of this time without companionship or supervision by responsible adults (Carnegie Council on Adolescent Develop ment 1992). Discretionary time outside of school represents an enormous poten tial for either desirable or undesirable behaviors, such as alcohol and other drug use. Several studies have found that young adolescents who are more likely to be without adult supervision after school have significantly higher rates of alcohol, tobacco, and marijuana use than do ado lescents receiving more adult supervision (Mulhall et al. 1996;Richardson et al. 1993). Scales and Leffert (1999) conducted a comprehensive literature review on the effects of involvement in youth programs (e.g., sports, recreation, camps, mentoring, and drop-in centers) on adolescent development. They found that involvement in youth programs is associated with the following outcomes: Another study also found involve ment in extracurricular activities to be related significantly to reduced adoles cent alcohol, tobacco, marijuana, and other drug use (Jenkins 1996). Widely cited meta-analyses (e.g., Tobler 1992) compared the effectiveness of two types of extracurricular programs: peer programs and alternative programs. Peer programs were defined as interventions that included social and life skills train ing, including refusal skills. Alternative programs were defined as interventions that included the provision of positive activities more appealing than drug use (e.g., sports activities). The meta-analyses found that alternative programs overall were less effective than peer programs. Among the alternative programs, those that involved high-risk youth and that involved many hours of activities were most effective.
Similar findings were reported in a review of alternative programs published by the Center for Substance Abuse Prevention (CSAP) (Carmona and Stewart 1996). That report concluded that there was no strong research support for the alternative approach. The review offered the following conclu sions based on the available research: • Alternative approaches seem to be most effective with high-risk youth who may not have adequate adult supervision and a variety of activities available to them in their daily life.
• Youth involvement in the planning and implementation of alternatives may enhance participation and effectiveness.
• More intensive programs seem to be most effective.
• Alternative programs should incor porate skills-building components into their design.
• Alternative programs should be one part of a comprehensive prevention plan serving to establish strong com munity norms against alcohol use.
As noted by Carmona and Stewart (1996), an important component of extracurricular activities appears to be active youth leadership. This conclu sion was supported by a study by Komro and colleagues (1996), who reported that youth who participated in planning alcohol-free activities for their peers significantly reduced their alcohol use. However, more research using rigorous controlled designs is needed to understand the effects of involvement in extracurricular activities and youth leadership on early onset of alcohol use.

Family Strategies
Several sources have recommended family involvement as important for the suc cess of alcohol prevention strategies (Drug Strategies 1996; Dusenbury and Falco 1995; National Institute on Drug Abuse [NIDA] 1997). Family factors, such as parent-child relationships, dis cipline methods, communication, mon itoring and supervision, and parental involvement, can significantly influ ence alcohol use among youth (Bry et al. 1998). Because of increasing demands on their time and attention, however, parents are spending less time with their children and therefore need strate gies and ideas to help them effectively parent their children (Kumpfer 2000).
Promising family strategies for preventing alcohol, tobacco, and other drug use include structured, home-based parent-child activities; family skills train ing; behavioral parent training; and behavioral family therapy. Reviews of family skills training indicate that enhancement of the following parent ing skills is important for the preven tion of alcohol use (Ashery et al. 1998;NIDA 1997 Various studies have identified sev eral components that contribute to the success of family based prevention interventions. One major component is a focus on skill development rather than on simple education about appro priate parenting practices (Etz et al. 1998). Another important component is the involvement of both parents and children in individual and group train ing sessions (Etz et al. 1998). Several studies have found that parent and family training programs both improve parenting skills and reduce problem behaviors among children (Ashery et al. 1998;NIDA 1997).
Examples of successful parenting programs include the Preparing for the Drug-Free Years (PDFY) program and the Iowa Strengthening Families Program (ISFP) (Kumpfer et al. 1996;NIDA 1997;Spoth et al. 1999a,b). The PDFY program consists of five competencytraining sessions for parents, with young adolescents attending one of those ses sions together with their parents. The ISFP comprises seven sessions, each attended jointly by youth and their parents. Comparisons of both interven tions with control families found positive effects on parents' child management practices and parent-child relations, improved youth resistance to peer pres sure toward alcohol use, reduced affilia tion with antisocial peers, reduced lev els of problem behaviors, and delayed substance use initiation (Kumpfer et al. 1996;Spoth et al. 1999a,b).
A less intense family involvement approach is based on including parents in homework assignments around issues of alcohol use, thereby increasing the likelihood that alcohol, tobacco, and other drug use is discussed at home, and potentially enhancing parenting skills by increasing communication between parent and child and providing behav ioral tips to parents. For example, Project Northland, which is described later in this article, used homework assign ments to engage families and provide behavioral tips.

Policy Strategies
Adolescent alcohol use also is determined by important environmental influences, such as the legal, economic, physical, and social availability of alcohol (Wagenaar and Perry 1994). Accordingly, lawmak ers have implemented several policy strategies targeting these influences to reduce the availability of alcohol to youth. These strategies include raising the minimum legal drinking age (MLDA), curtailing commercial access, limiting social access, and reducing economic availability.

Increasing the MLDA
The effectiveness of alcohol policies in significantly reducing alcohol-related problems has been well demonstrated by changes in the MLDA and the result ing consequences. During the early 1970s, 29 States lowered their MLDA, typically from age 21 to ages 18, 19, or 20. As concern about increasing rates of alcohol-related traffic crashes among young people grew, however, a grassroots movement developed in many States, putting pressure on State governments to raise the MLDA back to age 21. In 1984, the Federal government passed the Uniform Drinking Age Act, which provided for a reduction in Federal funds to States that did not raise their MLDA to age 21, and by 1988, all States again had a MLDA of 21.
The MLDA is the most-studied alco hol policy, with 132 published studies (Wagenaar and Toomey 2001). Included in these are well-controlled investigations providing clear evidence that a higher MLDA can effectively reduce drinking as well as alcohol-related car crashes and other injuries among teenagers.
Though effective, the increase in MLDA to age 21 has had only modest enforcement 1 (Wagenaar and Wolfson 1994). For example, youth report that they have easy access to alcohol from both licensed establishments and social sources (e.g., friends or acquaintances) (Wagenaar et al. 1996). These reports are substantiated by purchase-attempt studies, which directly test the propen sity of establishments to sell alcohol to youth without requiring identification. In the early 1990s, such studies found that young buyers could purchase alcohol with no age identification in approxi mately 50 percent of the purchase attempts (Forster et al. 1995). In addi tion, youth frequently receive alcohol from social providers, including parents, friends, coworkers, and even strangers (Wagenaar et al. 1996). Accordingly, public health professionals and activists in many communities are working to reduce youth access to alcohol from both commercial and social providers using public and institutional policy changes, such as the ones described in the following sections.

Policies to Reduce Commercial Access
To address the problem of alcohol availability from commercial providers, communities have conducted enforce ment campaigns using compliance checks. During these checks, law enforce ment officers supervise attempts by underage youth to purchase alcohol from licensed establishments. When an illegal sale is made, penalties are applied to the license holder and/or the clerk or server who made the sale. Such compli ance checks can significantly reduce sales to minors (Preusser et al. 1994;Grube 1997). State and local laws pro viding for graduated administrative (as opposed to criminal) fine and license suspension penalties for establishments that sell to minors may improve the effectiveness of these enforcement efforts because the increased certainty of penalties is a key component of deterrencebased approaches (Ross 1992).
Other policy tools to reduce youth access to alcohol from commercial sources include requiring servers of alcohol to be trained to detect false age identifica tion, designing drivers' licenses to clearly 1 The little enforcement that occurred in the late 1980s and early 1990s primarily involved citing underage drinkers rather than the adults who were illegally selling or provid ing alcohol to underage youth.
indicate whether someone is underage, and banning or regulating home deliv eries of alcohol. Studies evaluating servertraining programs show that such programs by themselves are unlikely to reduce sales to underage youth (Howard-Pitney et al. 1991;Toomey et al. 2001). Training programs may be useful, however, for creating a political climate that decreases resistance to enforcement campaigns that can effectively reduce sales to minors.
Home deliveries of alcohol may make it even easier for youth to obtain alco hol from a retail establishment because the transaction occurs in completely unmonitored settings. Approximately one-half of the States in the United States allow alcohol delivery from retail establishments to private residences. The only published study of teen use of home delivery found that 10 percent of the 12 th graders and 7 percent of the 18-to 20-year-olds reported consum ing home-delivered alcohol (Fletcher et al. 2000). A limitation of this study is that it did not ask whether it was the underage youth or an adult who had ordered the delivery of alcohol.
Recently, State and national policymakers have proposed restrictions on home delivery of alcohol ordered from Internet sites. Although debates over these controversial proposals involve apparent concern for reducing youth access to alcohol, home delivery from local retail outlets is a more likely source of alcohol than Internet orders, at least in part because it provides more imme diate access to alcohol. Internet sales require youth to plan weeks in advance to purchase alcohol for a drinking event, require a credit card, involve careful planning when and where the alcohol will be delivered, and potentially require storage until the drinking event occurs. Restrictions on retail home deliveries of alcohol, however, are not included in the policy debates on Internet sales; therefore, it appears that policy atten tion to alcohol Internet sales may have more to do with the varying economic interests of local versus national alcohol distributors and retailers. The effects of restrictions on Internet or retail home deliveries on youth alcohol use have not been studied.

Policies to Reduce Social Access
Policy tools for limiting youth access to alcohol from social providers attempt to reduce the frequencies of underage drinking parties and of adults illegally providing alcohol to youth. Some of these prevention approaches are being implemented at the community level. For example, communities may address underage drinking parties by creating enforcement mechanisms, such as noisy assembly ordinances, that allow law enforcement officers to enter private residences where underage drinking is occurring. 2 Communities can also require beer kegs to be registered at the time of retail sale. Using a keg's unique identification number and the registra tion information, police officers can identify and penalize adult purchasers of kegs used at parties where underage guests are caught drinking. To deter adults from illegally giving alcohol to youth, some States have enacted social host laws that allow third parties to sue social providers when provision of alco hol to youth results in a death or injury. Although many possible policy strategies have been identified that may help reduce social access to alcohol, lit tle research has been done to evaluate the specific effects of these strategies.

Policies to Reduce Economic Availability
Policies also can help reduce the eco nomic availability of alcohol. A large number of econometric studies have clearly demonstrated an inverse rela tionship between price and consump tion of alcohol-that is, higher prices result in reduced consumption. (For more information on the effects of price on alcohol consumption, see the article in this issue by Chaloupka and colleagues, Policy simula tion studies suggest that this relationship exists among the general popula tion as well as among adolescents. Thus, higher alcohol prices may sub stantially reduce both the frequency and the amount of teen drinking, even among youth who are already heavy alcohol consumers (Laixuthai and Chaloupka 1993). In fact, price increases may be particularly effective in reducing youth drinking, because heavy drinkers in young populations are more affected by price than are heavy drinkers in the general population (Godfrey 1997;Chaloupka and Wechsler 1996).
One policy that has been used to raise the price of alcohol is to increase the excise tax on alcohol. Although alcohol excise taxes are often raised for revenue-generating reasons, several studies suggest that higher excise taxes may affect youth consumption and its consequences. Higher taxes on alcohol are associated with less drinking among 16-to 21-year olds (Grossman et al. 1994) and high school students (Lockhart et al. 1993). Higher taxes are also asso ciated with fewer traffic fatalities among youth (Saffer and Grossman 1987), higher graduation rates from college (Cook and Moore 1993), and less violence among college students.

Community Strategies
Community participation is critical for creating comprehensive changes in insti tutional policies (e.g., of alcohol estab lishments, media outlets, and schools) and public policies aimed at reducing youth access to alcohol. Several commu nity trials have included communityorganizing components to mobilize and successfully change policies addressing public health issues (Wagenaar et al. 2000a;Holder et al. 1997).
Only one community trial-Communities Mobilizing for Change on Alcohol (CMCA)-has focused solely on policy changes to reduce youth access to commercial and social sources of alcohol. CMCA tested a community-organizing intervention in a trial involving 15 communities that were randomly assigned to receive the intervention or to serve as control com munities. The goal of the communityorganizing intervention was to reduce the accessibility of alcoholic beverages to youth under age 21. Through the organizing effort, diverse groups of people across the intervention communities 2 An example of such an ordinance can be found on the Internet at www.epi.umn.edu/alcohol. developed and implemented strategic action plans to influence a wide array of institutional policies (Wagenaar et al. 1999). The intervention was suc cessful in several respects. For example, it changed alcohol merchant practices around selling to underage youth and reduced the propensity of 18-to 20year olds to buy alcohol in a bar, provide alcohol to other teens, or consume alcohol (Wagenaar et al. 2000a). Furthermore, following the intervention, arrests for driving under the influence among 18-to 20-year olds were significantly lower in the intervention communities than in the control communities (Wagenaar et al. 2000b).
Two other community trials-the Community Trials Project (CTP) and the Saving Lives Program-have also addressed underage drinking, although the focus of these studies expanded beyond the underage population. The goal of the CTP was to reduce injury and deaths related to alcohol use among all age groups (Holder et al. 1997 Following the intervention, sales rates to buyers who appeared to be under age 21 were lower in the three intervention communities than in the three comparison communities (Grube 1997). The intervention communities also showed reductions in self-reported drinking-and-driving rates, nighttime injury crashes, alcohol-related crashes, and assault injuries among the general population (Holder et al. 2000).
The Saving Lives program, which was conducted in six communities in Massachusetts, also involved commu nity mobilization to address drinking and driving among all age groups (Hingson et al. 1996). The interven tion included multiple strategies that addressed alcohol-impaired driving as well as other traffic problems, such as speeding, other moving violations, and seat belt use. Following the intervention, the relative decrease in alcohol-involved fatal traffic crashes was 42 percent in the intervention communities compared with the rest of the State (the absolute change was from 69 crashes to 36 crashes in the intervention communi ties). Furthermore, self-reported drink ing-and-driving among 16-to 19-yearolds was reduced by 40 percent in the intervention communities compared with the rest of Massachusetts.

Multicomponent Strategies
Although various individual strategies have been successful in preventing youth alcohol use, a more comprehen sive approach combining several of the intervention strategies described above might be even more effective. Two studies-the Midwestern Prevention Project and Project Northland-have combined school, family, and commu nity strategies to prevent alcohol use among adolescents; their results are described in the following sections.

Midwestern Prevention Project
The Midwestern Prevention Project, which was not specific to alcohol use but addressed all types of drug use, con sisted of the following four components: • A 10-session school program emphasizing drug-use-resistance skills training, delivered in grade 6 or 7; this component also included homework sessions involving active interviews and role plays with par ents and family members • A parent organizations program for reviewing school prevention policy and training parents in positive parentchild communication skills • Initial training of community lead ers in the organization of a drug abuse prevention task force • Mass media coverage of the program.
The study was composed of eight representative Kansas City communi ties that were randomly assigned either to the full program including all four components or to a control program including only the community organi zation and mass media components. After 3 years, students in the commu nities implementing the full program had lower rates of tobacco and mari juana use, but not alcohol use; this fol lows the previously described findings that alcohol use patterns appear to be the most difficult to change.

Project Northland
Project Northland was designed to prevent or reduce alcohol use among young adolescents using a comprehen sive, multicomponent intervention that targeted both the supply of and demand for alcohol. Project Northland was evaluated using 20 school districts from northeastern Minnesota that were randomly assigned either to the treat ment or control condition. The stu dents participating in the study were surveyed from grades 6 through 12. The intervention was conducted in three stages: a first intervention phase, an interim phase, and a second inter vention phase. The first intervention phase, which was conducted when the students were in grades six through eight, included: (1) social behavioral curricula, (2) peer leadership and extracurricular social opportunities, (3) parental involvement and educa tion, and (4) community-wide task forces (Perry et al. 1993b). At the end of 3 years, a smaller percentage of stu dents in the intervention communities reported drinking or beginning to drink compared with students in the control communities. Furthermore, among students in all districts who at the beginning of sixth grade reported never having consumed alcohol, those in the intervention communities were not only less likely to drink 3 years later but also had lower rates of cigarette and marijuana use .
The interim phase of the study occurred when the students were in grades 9 and 10. During those years, only minimal intervention (i.e., a five-session classroom program) took place, and drinking rates between the treatment and control groups began to converge. In fact, by the end of grade 10, no signifi cant differences existed between the two groups (Williams and Perry 1998).
In the second intervention phase, when the students were in grades 11 and 12, they were exposed to various interventions, including an 11 th grade classroom curriculum, parent postcards, mass media involvement, youth development activities, and community organizing (Perry et al. 2000). As a result of the intensified intervention, the alcohol use patterns of the treatment and control groups began to diverge again by the end of the 11 th grade, and the differences between groups were marginally significant for those students who had not used alcohol at the begin ning of 6 th grade (Williams et al. 1999).
An analysis comparing the trajectories of alcohol use between the treatment and control groups (i.e., a growth curve analysis) was conducted for all three phases of Project Northland. During the first intervention phase, the increase in alcohol use was significantly greater in the control group than in the inter vention group. Conversely, the increase in alcohol use was significantly greater in the intervention group than in the control group during the interim phase, when there were minimal program efforts. Thus, the students in the inter vention group seemed to return to the level of drinking that was normative in their communities. Fortunately, that trend was reversed again during the second intervention phase. During that period, the increase in alcohol use was again greater in the control group than in the intervention group (p<0.02), demonstrating the positive and signifi cant impact of the second intervention phase (Perry et al. in press). In addition, the community-organizing intervention component during the second interven tion phase, which focused on commu nity action team-initiated compliance checks of alcohol outlets, successfully reduced the ability of youthful-appearing 21-year-olds to purchase alcohol without age identification (p=0.05) (Perry et al. in press).

Conclusion
Adolescent alcohol use is one of the most difficult behaviors to change because alcohol use is so ingrained in the U.S. culture. Adolescents choose to consume alcohol, not just because of personal characteristics, such as personality type or level of social skills, but also because it is a part of daily life in their commu nities and, for many youth, in their homes (Wagenaar and Perry 1994). As Wagenaar and Perry indicate in their theoretical model (1994), numerous social and environmental influences affect adolescents, including messages they receive from advertisements, commu nity practices, adults, and friends about alcohol. Comprehensive interventions targeting underage drinking may need to counter or change all of these mes sages to motivate individual adolescents to choose not to consume alcohol.
Researchers' knowledge about effec tive interventions to reduce underage drinking-particularly about schoolbased programs targeting individuallevel factors-has grown substantially during the past decade, and investiga tors have identified key components of state-of-the-art school-based programs. By themselves, however, these programs are unlikely to create sustained reduc tions in underage drinking. Instead, school-based programs may need to be combined with extracurricular, family, and policy strategies that help change the overall social and cultural environ ment in which young people live to create sustained decreases in consump tion and alcohol-related problems among youth.
Although key components of nonschool-based strategies have been iden tified, further research is needed in many of these areas to understand fully what factors must be targeted and what methods can best achieve those targets and reduce underage drinking. As researchers, clinicians, and policymak ers learn more about each strategy, they need to synthesize this knowledge to develop multicomponent projects con sisting of high-quality and complemen tary components that together create interventions strong enough to overcome the drinking culture found throughout U.S. communities. I